Artificial Foot And Method  For Controlling The Movement Thereof

ABSTRACT

An artificial foot having a longitudinal axis extending from a heel area to a toe area, a length, a width and a height is provided. The artificial foot includes a connection to a lower leg part, an upper supporting structure in the direction of height, an elastic sole structure extending from the heel area to the toe area, an elastic connecting element arranged between the upper supporting structure and the sole structure, and a coupling system. The upper supporting structure is connected to the sole structure approximately in a middle of the foot with respect to its length by means of the coupling system. The coupling system allows a relative tilting motion between the upper supporting structure and the sole structure while keeping a distance between the upper supporting structure and the sole structure in a middle of the coupling system constant, at least while a patient places weight on it when standing.

CROSS-REFERENCE TO RELATED APPLICATION

This patent application is a national stage application of InternationalApplication No. PCT/DE2007/000057 filed Jan. 16, 2007, which claimspriority to German Patent No. DE 10 2006 004 132.1, filed on Jan. 27,2006. The entire content of these applications are hereby expresslyincorporated by reference.

TECHNICAL FIELD

The invention relates to an artificial foot with a longitudinal axisextending from a heel area to a toe area, a length, a width and aheight, a connection to a lower leg part, a supporting structureuppermost in the direction of height, an elastic sole structureextending from the heel area to the toe area and an elastic connectingelement arranged between the upper supporting structure and the solestructure.

The invention further relates to a method for controlling movement of anartificial foot depending on the movement of a lower leg part of apatient.

BACKGROUND

It is known to attach an artificial foot to a lower leg part of apatient such that the foot structure manages without a joint in theregion of the natural ankle joint. The flexing action of the foot duringwalking is accomplished by corresponding elastic formations of the footstructure.

U.S. Pat. No. 5,993,488 discloses a foot structure which includes anupper connection plate, an ankle plate connected solidly to theconnection plate and a somewhat bulged sole plate. At the same time thesole plate has approximately the length of the artificial foot and isflexible in a longitudinal direction. The ankle plate is designedshorter and lies substantially parallel to the sole plate. Situatedbetween the ankle plate and the sole plate is a foam block made ofrelatively firm, though elastic, foam. The foam block has across-sectional area for a horizontal cut which correspondsapproximately to the cross-sectional area of the ankle plate so that thefoam block fills out the interstice between the ankle plate and the soleplate over the entire size of the ankle plate. The parts are connectedto one another by adhesion and are secured against delaminating by aband looped around the sole plate and the ankle plate with theinterposed foam block. This foot structure causes compression of thefoam block, resulting in a shift of the force transfer from the ankleplate to the sole plate correspondingly with the displacement of weightfrom rear to front. This can be meaningful for a user's gait, andparticularly for heel-toe walking on the foot. However it may lead to anunsteady feeling when standing if slight displacements in weight lead tocorresponding displacements of the introduction of force between theankle plate and the sole plate. This gives the patient an unsteady“wobbly” feeling, since there is no defined point for introducing weightforces to the foot construction. This also applies for lateraldisplacements of weight and for displacements of weight in intermediatedirections oblique to the longitudinal axis of the foot.

U.S. Pat. No. 4,446,580 discloses a foot construction in which a tubularlower leg part is connected to a base plate via a hinge joint offsetforwards with respect to its longitudinal axis. The lower leg part isguided relative to a guide rod attached flexibly to the base plate,whereby the pivoting motion of the lower leg part around the hinge jointin the base plate is damped by means of plastic dampers. The base plateis solidly anchored in a recess of a sturdy artificial foot. Anelastically spring-loaded sole structure and heel strike dampingconnected thereto are not provided.

SUMMARY

One aim of the present invention is to provide movement of theartificial foot, which on the one hand provides uniform heel-toe walkingand on the other hand provides a secure feeling for standing.

An artificial foot of the abovementioned type according to oneembodiment of the present invention includes an upper supportingstructure connected approximately in the middle of the foot with respectto its length to a sole structure by a coupling system. The couplingsystem allows a relative tilting motion between the supporting structureand the sole structure and at the same time keeps the distance betweenthe supporting structure and the sole structure in the middle of thecoupling system constant, at least as the patient places weight on itwhen standing.

In another embodiment the multiaxial and flexible movement of the lowerleg part is provided by an elastic sole structure having a supportingstructure at an introductory point in a middle region relative to thelength of the foot such that, at least when the patient is standing,there is no change in distance between the supporting structure and thesole structure at the introductory point. In the heel area, the movementof the elastic sole structure is elastically damped in the direction ofthe supporting structure and is limited in the direction away from thesupporting structure.

According embodiments of the invention the transfer of forces of thelower leg part to the sole structure is made at a defined introductorypoint at which the supporting structure is multiaxially and flexiblyconnected to the sole structure to provide a relative tilting motionbetween the supporting structure and the sole structure when the solestructure is elastically damped. In addition the distance between thesupporting structure and the sole structure in the middle of thecoupling system at the introductory point remains unchanged, at leastwhen the patient is standing, so that the introduction of force remainsunchanged at the introductory point, i.e. in the centre of the foot.

This applies in principle also for heel-toe walking action duringwalking. Yet it is possible at the same time through reducing thedistance via greater compression forces arising from walking at theintroductory point to enable slight rearwards displacement of the forceintroduction point, since the force vector effective between thesupporting structure and the sole structure through the tilting motionof the supporting structure forwards migrates slightly rearwards. Thisleads to comfortable heel-toe walking action and to a feeling ofheightened security in heel-toe walking.

In a particular embodiment of the inventive artificial foot, thecoupling system includes a hinged arrangement formed, for example, by amaterial piece which can be compressed by tilting moments on part of itscross-section, but is not compressed in its length by the forceoccurring from standing. This compression, which causes a reduction inthe cylinder length, is permitted only by higher forces, such as thosethat occur during walking. The material piece particularly has the formof a cylinder of any cross-section and particularly the form of acircular cylinder.

The elastic connecting element is arranged in the inventive artificialfoot only in the heel area in one embodiment, and therefore it does notextend uniformly over the entire length of the supporting structure. Theelastic connecting element can be a bent leaf spring or other springsystem, such as an elastic pad made of plastic foam material.

A limiting device of the elastic connecting element is a flexible andinelastic band which is tensible in the case of increasing distance ofthe upper supporting structure from the sole structure, such as inparticular during heel-toe walking by the artificial foot across the toeregion.

The flexible band may be guided with deflection through the elastic padso that elastic displacement of material of the elastic pad tenses theband. This makes it possible to control the forefoot resistance duringheel-toe walking via the forefoot by guiding the flexible band throughthe elastic pad or respectively around the elastic pad and thus to adaptit to the needs of the patient.

In one embodiment, the upper supporting structure includes a rigidmaterial, or at least a material having an elasticity less than theelasticity of the sole structure.

In one embodiment of the inventive foot, the hinged arrangement isarranged on the toe-side end of the upper supporting structure. In otherwords, the upper supporting structure ends appropriately on the hingedarrangement.

In another embodiment, the upper supporting structure has an undersidewhich rises from the toe-side end relative to the sole structure so thatthe heel-side end is a greater distance from the sole structure than inthe region of the coupling system.

For easy installing of the inventive artificial foot, the elastic padhas a horizontal slot into which the sole structure is inserted. In oneembodiment, the flexible band forming the limiting device is loopedaround the underside of the sole structure. The upper supportingstructure can then have a lug around which the band can loop on its topside.

The inventive artificial foot also allows a stable standing functioneven with different heel heights for a shoe worn on the artificial footby providing a lockable height-adjustment device, with which thedistance between the sole structure and the upper supporting structurecan be adjusted, in terms of power flow in series with the elasticconnecting element. The angle between the upper supporting structure andthe sole structure can be adjusted by way of the height-adjustmentdevice, whereby adaptation to different heel heights is possible.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained hereinbelow in greater detail by meansof exemplary embodiments illustrated in the diagram, in which:

FIG. 1 shows a schematic illustration of the structure of an inventiveartificial foot in a first embodiment;

FIG. 2 shows an exemplary embodiment for an arrangement of a flexible,however inelastic band serving as a limiting device;

FIG. 3 shows a modified arrangement of the band for controlling forefootresistance during heel-toe walking;

FIG. 4 shows a schematic illustration according to FIG. 1 for a secondembodiment of an inventive artificial foot;

FIGS. 5 to 7 show three phases for fitting the artificial foot accordingto FIG. 1;

FIG. 8 shows a schematic illustration of a third embodiment of aninventive artificial foot;

FIG. 9 shows a schematic illustration of a fourth embodiment of aninventive artificial foot;

FIG. 10 shows a schematic illustration of a fifth embodiment of aninventive artificial foot;

FIG. 11 shows a schematic illustration of a sixth embodiment of aninventive artificial foot; and

FIG. 12 shows two schematic illustrations of a seventh embodiment of aninventive artificial foot, provided with a height-adjustment device.

DETAILED DESCRIPTION

FIG. 1 illustrates a cosmetic sheath 1 of an artificial foot in dashes.A sole structure 2 extends essentially over the entire length of thefoot. The sole structure 2, when viewed from below in a toe area, has aconvex arching which transitions approximately in the middle of the footinto a concave arching that may extend as far as a heel area. The solestructure 2 in the illustrated exemplary embodiment includes a flat,striated, long stretched-out sole spring 21. Approximately in the middleof the foot the sole structure 2 is connected to a front end of asupporting structure 3 via a coupling system formed by a hingedarrangement 4. The hinged arrangement 4 includes a material piece 5 inthe form of a plastic cylinder, supported by a lower front end on thesole structure 2 and by an upper front end on an underside of thesupporting structure 3. In the illustrated embodiment the hingedarrangement 4 is complemented by a pin arrangement 6 which has ballpointattachments 7, 8 at both its ends. The ballpoint attachments 7, 8 aresupported on the sole structure 2 on the one hand and on the supportingstructure 3 on the other hand. The ballpoint attachments 7, 8 increasethe stability of the connection between the supporting structure 3, thecylinder 5 and the sole structure 2, without hindering relativetiltability of the supporting structure 3 relative to the sole structure2.

The relative tiltability results from an elastic configuration of thecylinder 5. The cylinder 5 can be pressed in by inclinations of thesupporting structure 3 relative to the sole structure 2 on part of itscross-section by the weight forces of a patient wearing the artificialfoot. As a result, the opposite part of the cylinder 5 diametrical incross-section expands such that the average height of the cylinder 5,and therefore the resulting average distance between the supportingstructure 3 and the sole structure 2 in the region of the hingedarrangement 4, remains constant.

A lessening of the middle distance is permitted due to forming thecylinder 5 to be pressed in only by higher forces, such as those thatoccur on the hinged arrangement 4 with heel-toe walking of the footduring walking.

The supporting structure 3 has an underside 9, which rises from thehinged arrangement 4 to the heel area relative to the sole structure 2,so that the distance between supporting structure 3 and sole structure 2increases from the hinged arrangement 4 to the heel area. An elasticconnecting element 10, in the form of an elastic pad 101 is arranged, inthe heel area between the supporting structure 3 and the sole structure2. The elastic pad 101 includes a limiting device in the form of aflexible band 11, which fixes a maximum distance between the supportingstructure 3 and the sole structure 2 in the region of the band 11, asshown in greater detail in FIGS. 2 and 3.

The supporting structure 3 has on its top side an adjusting trunnion 30,to which a connection to a corresponding lower leg part of a lower legprosthesis can be attached.

FIG. 2 shows that the flexible, but inelastic, band 11 is positionedinside the elastic pad 101 and loops around the underside of the solestructure 2. For receiving the sole structure 2 the elastic pad 10 isprovided with a continuous horizontal slot 12, illustrated in FIG. 1 bydots. The endless band 11 loops around a cylindrical lug 13 on theunderside of the supporting structure 2.

FIG. 2 shows the tensed state of the band 11 at the maximum distancebetween the supporting structure 3 and the sole structure 2. It isevident that with a heel strike the elastic pad 10 can compress, tocause the flexible band 11 to transition from the tensed state into aslack state, with a wrinkle. By subsequently expanding the elastic pad10 or by loading the forefoot area of the sole structure 2, the flexibleband 11 is returned to the tensed position illustrated in FIG. 2.

FIG. 2 further discloses that the underside 9 of the supportingstructure 3 has a roof-like design and that the elastic pad 10 includesa corresponding roof-like top side that rests on the roof-like underside9 of the supporting structure 3 and can be adhesively bonded thereon.

In the exemplary embodiment illustrated in FIG. 3, the band 11 runsbetween the sole structure 2 and the lug 13 inside the elastic pad 10along a bent line. To limit the maximum distance between the supportingstructure 3 and the sole structure 2, the band 11 is tensed in such away that it forms a straight line between the lug 13 and the lateraledges of the sole structure 2. For this to happen, the band 11compresses areas of the elastic pad 10 to the side so that elasticdamping occurs with increasing distance between the sole structure 2 andthe supporting structure 3 caused by forefoot loading of the solestructure 2. The flexing action of the forefoot of the sole structure 2is thus possible with increased resistance to control the forefootresistance of the artificial foot via the arrangement of the flexibleband 11.

The embodiment illustrated in FIG. 4 differs from the embodimentillustrated in FIG. 1 only in that the supporting structure 3transitions in one piece into a lower leg part 14, such that noconnection needs to be made between the lower leg part 14 and thesupporting structure 3.

The inventive artificial foot is assembled by connecting the supportingstructure 3 to the sole structure 2 via the hinged arrangement 4,resulting in a heel area open to the rear. The elastic pad 10 isinserted into the conically opened interstice between the supportingstructure 3 and the sole structure 2 by pushing the sole structure 2 byits rear end into the slot 12 serving as a recess, as is shown in FIG. 6in an intermediate position. As the elastic pad 10 is pushed in further,the flexible band 11, which projects from the top side of the elasticpad 10 by a loop, is pushed over the lug 13 (not illustrated in FIGS. 5to 7). After the elastic pad 10 is fully slid on when the limitingdevice in the form of the closed circular flexible, but inelastic, band11 is being installed, the elastic pad 10 can be connected via ahardening adhesive to the supporting structure 3, and where necessary tothe sole structure 2.

The effect of the roof-like configuration of the underside 9 of thesupporting structure 3 and the corresponding roof-like configuration ofthe top side of the elastic pad 10 is to automatically center theelastic pad 10 in connection with the guiding caused by inserting thesole structure 2 into the take-up slot 12.

As in FIG. 1 and FIG. 4, FIG. 7 shows that the part of the elastic pad10 protruding beneath the sole structure 2 can serve as a damper for thesole structure 2 during heel strike. Any shaping of the elastic pad 10on this underside favors the heel-toe walking action during heel strike.

The hinged arrangement formed by the cylinder 5 in the illustratedexemplary embodiments can also be designed differently, for example inthe form of a universal ball joint, which cooperates with acorresponding ball socket. This would form a tiltable connection betweenthe supporting structure 3 and the sole structure 2 without altering thedistance between the supporting structure 3 and the sole structure 2 atthe introductory point of force in the region of the hinged arrangement4 when the patient stands. Due to the higher forces during walking, forexample, the universal ball joint can be made of a plastic indented bythese forces, or hard rubber.

A third embodiment of an inventive artificial foot illustrated in FIG. 8has an elastic connecting element 10 between the supporting structure 3and the sole structure 2 in the form of a control spring 102. Thecontrol spring 102 is designed as a two-armed spring part with a middlepiece 15 that forms part of the hinged arrangement 4. The middle piece15 is provided on its top side with a concave arching, in which acorresponding convex arching of the toe-side end of the supportingstructure 3 rests. The underside of the middle piece 15 is likewisearched concavely to the underside and rests on a corresponding convexarching of a plastic damper 16. The hinged arrangement 4 is heldtogether by a pin arrangement 6.

The control spring 102 is connected to a heel-aligned arm 17 at theheel-side end of the supporting structure 3 by means of a fixing screw18. A toe-aligned arm 19 of the control spring 102 runs approximatelyparallel to the toe-side end of a sole spring 21. In this area thetoe-aligned arm 19 of the control spring 102 and the sole spring 21 areconnected via an elastic damper 20 and two flexible, but inelasticretaining straps 22, 23 are arranged on both sides of the damper 20.

With heel strike during walking the heel-aligned arm 17 of the controlspring 102 is deformed elastically downwards, i.e. in the direction ofthe heel-side end of the sole spring 21. Apart from the deforming of theheel-aligned arm 17 damping the heel strike, upwardly directed torqueoccurs on the toe-aligned arm 19 of the control spring 102. While thefoot performs plantar flexion with respect to the lower leg part 14, thetoe area of the foot is raised by the toe-aligned arm 19 of the controlspring 102, making heel-toe walking of the foot easier.

The flexible retaining strap 23, arranged between the middle piece 15and the elastic damper 20, is adjustable in a longitudinal directionsimilar to the elastic damper 20, as indicated by the arrows in FIG. 8.A shift of the flexible retaining strap 23 (illustrated here in themiddle) between the middle piece 15 and the toe-side end of the solestructure 2 leads to reduction of the resulting hardness of theheel-aligned arm 17 of the control spring 102. The heel strike is dampedmore softly. The position of the elastic damper 20 acts independently asadjusting means of the forefoot hardness of the sole structure 2. Theforefoot becomes stiffer as the elastic damper 20 approaches theforefoot tip. The sole spring 21 and the control spring 102 aresynchronized such that desired plantar flexion occurs during heelstrike.

In a fourth exemplary embodiment illustrated in FIG. 9, the elasticconnecting element 10 is again formed substantially by the elastic pad101 in the heel area. The flexible band 11, which limits the maximumdistance between the rear end of the supporting structure 3 and theheel-side end of the sole structure 2, is looped through a rearwardsopen slot 24 of the supporting structure 3. The control spring 102projects into the elastic pad 101 with its heel-aligned arm 17. Thecontrol spring 102 substantially forms part of the sole structure 2. Theforefoot rigidity can be adjusted by the sizing and positioning of theelastic damper 20.

In a fifth embodiment illustrated in FIG. 10, the control spring 102 isconnected to the heel-side end of the supporting structure 3 by itsheel-side end again via the fixing screw 18. Also, the elastic pad 101for heel strike damping is arranged between the supporting structure 3or respectively the heel-aligned arm 17 of the control spring 102.Movement augmenting the distance between the supporting structure 3 andthe sole structure 2 in the heel area is restricted by the flexible band11.

Similarly to exemplary embodiment illustrated in FIG. 1, the hinge joint4 is formed by a pin arrangement 6 and two, plastic cylinders 5′, whichare arranged between the support structure 3 and the control spring 102on the one hand and between the control spring 102 and the sole spring21 on the other hand.

In this embodiment, the front ends of the control spring 102 and of thesole spring 21 are connected to one another by an elastic damper 25 anda flexible, but inelastic, retaining strap 26. The control spring 102and the sole spring 21 are synchronized such that plantar flexion occursduring heel strike. The heel stiffness can be adjusted by exchanging theelastic pad 101.

FIG. 11 shows an exemplary embodiment modified relative to FIG. 10, inwhich improved adjustment options are provided. As in the exemplaryembodiment illustrated in FIG. 8, shifting the flexible retaining strap23 to the heel-side end of the sole structure 2, causes damping by theheel-aligned arm 17 of the control spring 102 to be softer. The shift ofthe elastic damper 20 in a longitudinal direction causes a change in theforefoot hardness, whereby a shift of the elastic damper 20 to the toeend sets a greater hardness of the forefoot. Shifting of the plastic pad101 in a longitudinal direction and of the associated flexible band 11further influences the damping of the heel strike on the one hand andthe forefoot hardness on the other hand, because the length of theeffective heel-aligned arm 17 of the two-armed control spring 102 isaltered.

FIGS. 12 a and 12 b schematically illustrate a seventh embodiment of aninventive artificial foot. The illustrations schematically show the solestructure 2, the hinge joint 4, the upper supporting structure 3 and thelower leg part 14. The lower leg part 14 is connected rigidly to theupper supporting structure 3. In the heel area the elastic connectingelement 10 is provided, in particular in the form of a heel buffer. Thisis connected to the upper supporting structure 3 or respectively thelower leg part 14 not directly, but rather via a die 28 which isarranged to shift relative to the lower leg part 14 and can be fixed bymeans of a schematically illustrated locking member 29.

FIG. 12 a shows a seventh embodiment in a bare-foot position withoutadditional heel height from a shoe. FIG. 12 b shows by way of contrastthat the sole structure 2 has been reduced in its distance from thelower leg part 14 or respectively the upper supporting structure 3, soThis alters the angular setting of the sole structure 2 relative to thelower leg part 14 and the upper supporting structure 3 such thatadaptation to a heel height of a shoe is guaranteed. It is readilyevident that adaptations to different heel heights are possible viavarious adjustments of the die 28 relative to the lower leg part 14 orrespectively to the upper supporting structure 3.

The inventive construction enables a comfortable flexing action withdamped tilting motions corresponding to the natural foot, withoutcausing uncertainty for the patient due to changes in the forceintroduction point when standing. Due to the unchanged average distancebetween the supporting structure 3 and the sole structure 2 in theregion of the hinged arrangement 4, the inventive constructions leavethe force introduction point unaltered, in any case whenever the patientis standing. An advantageously minimal back displacement of the forceintroduction point for heel-toe walking can be implemented duringwalking.

1. An artificial foot with a longitudinal axis extending from a heelarea to a toe area, a length, a width and a height comprising: a adaptedto received a lower leg part; an upper support structure; an elasticsole structure extending from the heel area to the toe area; an elasticelement arranged between the upper supporting structure and the solestructure; and a coupling system which connects the upper supportstructure to the sole structure approximately in a middle of the lengthof the foot, by the coupling system providing a relative tilting motionbetween the upper supporting structure and the sole structure whilemaintaining a distance between the upper supporting structure and thesole structure in a middle of the coupling system constant, while apatient places weight on the coupling system when standing.
 2. Theartificial foot as claimed in claim 1, wherein the coupling system isformed by a material piece which can be compressed by tilting moments ona part of a cross-section of the material piece.
 3. The artificial footas claimed in claim 1, wherein the coupling system is compressed byhigher force to lessen a distance in the middle of the coupling system.4. The artificial foot as claimed in claim 1, wherein the elasticconnecting element includes an elastic pad.
 5. The artificial foot asclaimed in claim 4, wherein the elastic connecting element includes alimiting device limiting a distance between the upper supportingstructure and the sole structure.
 6. The artificial foot as claimed inclaim 5, wherein the limiting device includes a flexible band which istensible with increasing distance between the upper supporting structureand the sole structure.
 7. The artificial foot as claimed in claim 6,wherein the flexible band is guided with deflection by the elastic padso that elastic displacement by material of the elastic pad is requiredto tense the band.
 8. The artificial foot as claimed in claim 1, whereinthe upper supporting structure is formed from a rigid material.
 9. Theartificial foot as claimed in claim 1, wherein the coupling system isarranged on a toe-side end of the upper supporting structure.
 10. Theartificial foot as claimed in claim 1, wherein the upper supportingstructure has an underside which increases in distance from a toe-sideend to a heel-side end relative to the sole structure so that at theheel-side end, the underside is at a greater distance from the solestructure than a region of the coupling system.
 11. The artificial footas claimed in claim 4, wherein the elastic pad has a horizontal slotthrough which the sole structure is pushed.
 12. The artificial foot asclaimed in claim 6 wherein the flexible band is looped around anunderside of the sole structure.
 13. The artificial foot as claimed inclaim 12, wherein a lug which can be looped around by the flexible bandon a top side of the lug is arranged on the upper supporting structure.14. The artificial foot as claimed in claim 10, wherein the underside ofthe supporting structure has a roof-like heel area.
 15. The artificialfoot as claimed in claim 14, wherein an elastic pad with a roof-like topside rests on the roof-like heel area of the underside of the supportingstructure.
 16. The artificial foot as claimed in claim 1, wherein theelastic connecting element has a control spring with a heel-aligned arm.17. The artificial foot as claimed in claim 1 wherein a toe-aligned armof a control spring forms part of the sole structure, and wherein thetoe-aligned arm is connected to a front end of a sole spring of the solestructure.
 18. The artificial foot as claimed in claim 17, wherein theconnection of the toe-aligned arm to the sole spring occurs via anelastic damper.
 19. The artificial foot as claimed in claim 18, whereinflexible retaining straps limiting a distance between the sole springand the toe-aligned arm are arranged in a longitudinal direction on bothsides of the elastic damper.
 20. The artificial foot as claimed in claim4, wherein the elastic pad is arranged adjustably in a longitudinaldirection.
 21. The artificial foot as claimed in claim 1, wherein alockable height-adjustment device having power flow in series with theelastic connecting element, with which a distance between the solestructure and the upper supporting structure can be adjusted.
 22. Amethod for controlling movement of an artificial foot depending on amovement of a lower leg part of a patient, comprising the steps ofmoving the lower leg part multiaxially and flexibly by a supportingstructure in an elastic sole structure at an introductory point in amiddle region relative to a length of the foot, wherein when the patientis standing no change in distance between the supporting structure andthe sole structure occurs at the introductory point, and wherein in aheel area of the foot, movement of the elastic sole structure is dampedelastically in a direction of the supporting structure and is limited ina direction away from the supporting structure.
 23. The method asclaimed in claim 22, wherein a flexing action in a toe area of the footis controlled by the elastic sole structure.
 24. The method as claimedin claim 22, wherein a lessening of a distance is permitted betweensupporting structure and sole structure at the introductory point byhigher weight forces for heel-toe walking as the patient walks.